Standard Shrink Sleeves on Road Bore ApplicationsThe world of pipeline coatings is much like the world of tools. Different tools are designed for different functions. Brooms are great, and very effective when sweeping up dirt....but they are going to be pretty much useless if you're trying to cut down a tree. Likewise an axe is great for cutting down a tree, but is not going to be particularly effective for tightening a bolt. A wrench can tighten a bolt great, but it isn't going to be very effective if you're trying to dig a deep hole. Likewise; standard shrink sleeves are great for basic, drop the pipe in a ditch and backfill it types of applications; but they are quite simply: not designed for use in road bore applications.
WPCT is our most commonly sold ambient temperature, wrap around, heat shrink sleeve for corrosion prevention. It is a fantastic product. It has successfully prevented corrosion for decades on literally millions of field joints over the last decade. It is easy to install. It is reliable. It essentially inspects itself. But WPCT is not approved or recommended for use on road bore applications. That simply isn't what it is designed for.
The product that is specifically designed for road bore service is our DIRAX product. Incredible peel and shear resistance. Unparalleled abrasion resistance and penetration resistance. This sleeve is three times thicker than the WPCT product (on the leading edge of the coating). DIRAX uses a two part epoxy as the primary corrosion coating. That two part epoxy brings with it excellent cathodic disbondment resistance and improves the physical characteristics of the system (better peel / shear). The DIRAX sleeve is then installed over the wet epoxy. DIRAX is comprised of a three layer backing system and a high shear polyamide adhesive; which is designed to physically and chemically bond to the two part epoxy; forging a contiguous, bonded, thick field joint coating system that will easily withstand any forces it is put through during the boring process.
To sum up:
DIRAX for directional drilling: GOOD
WPCT for directional drilling: Not Good
Now, there are folks out in the world who will tell you that "WPCT will do just fine on a road bore." Please, do not believe those folks. They are just looking to make a quick and easy sale. They aren't evil people, they are simply uneducated. They want things quick and easy rather than spending the time to learn the ins and the outs of the Covalence heat shrinkable products product line.